Transportation officials are trying to convince the opponents of a $143 million project aimed at rearranging the Larkspur and Corte Madera stretch of Highway 101 that the proposed changes are necessary to increase safety and reduce highway bloodshed.

As the most accident-prone location in Marin County, the Larkspur-Corte Madera stretch of Highway 101 sees about 160,000 to 170,000 cars each day. Accidents are higher going northbound on the freeway toward San Rafael than southbound, according to Transportation Authority of Marin officials.

TAM's consultant David Parisi, with the Mill Valley-based Parisi Associates, said there have been 1,195 reported crashes in the area during a 10-year period, adding that for every reported accident there are two or three unreported ones. He said during that 10-year time frame, 556 people were injured. Two people were killed.

He said having so many onramps and offramps in close proximity along one small stretch of highway presents safety problems and worsens congestion.

"Collision rates are 30 to 100 percent higher than (the state) average at key weaving areas," Parisi said.

Dianne Steinhauser, TAM executive director, said officers with the California Highway Patrol will be on hand Tuesday at a special joint meeting of the Larkspur and Corte Madera councils to discuss safety issues in the corridor. The meeting takes place at 7 p.m. at the Corte Madera Recreation Center, 498 Tamalpais Drive.

The joint meeting is an extension of last week's public hearing in Larkspur, where the majority of the nearly 250 attendees expressed opposition to the proposed corridor changes. Changes include eliminating the Greenbrae pedestrian overcrossing and creating a 33-foot tall flyover to take drivers from southbound Highway 101 and Sir Francis Drake Boulevard into Corte Madera, ending at Wornum Drive.

Supporters of the construction project claim it will reduce traffic congestion, add $17 million in pedestrian and bicycle improvements and ultimately increase safety. Critics claim the project is outdated, monstrous and doesn't address traffic congestion on Sir Francis Drake Boulevard.

The project has been in the works for more than a decade. Caltrans initially wanted to close the Fifer Avenue and Madera Boulevard access ramps along southbound Highway 101 because they didn't meet the agency's engineering and safety standards.

Steinhauser said TAM fought with Caltrans to keep the ramps open, at the request of the community — which had concerns about negative impacts to surrounding businesses. She said about 11 project alternatives were proposed, but ultimately rejected by the community. Now they're left with an environmental document that has two options — build or no-build.

Larkspur Mayor Dan Hillmer said he thought the whole purpose of the project was to deal with traffic congestion coming from the Richmond-San Rafael Bridge to Highway 101 — not necessarily safety concerns. Especially since part of the funding is coming from the 2004 voter-approved Regional Measure 2, which increased tolls on state bridges by $1 for transportation improvement projects.

"It's funny how over a long period of time, focus can shift depending on who's working on it," Hillmer said.

He said TAM — which has committed gas tax revenue to the project — should explore lower impact, lower cost solutions to fix the highway's congestion problems.

Corte Madera Town Councilman Bob Ravasio said he too is a bit puzzled by TAM's heightened focus on safety.

"I understand it's not optimum and it's a little scary, but their own data doesn't support the fact that this needs to be corrected," Ravasio said. "The interchanges we're dealing with here are all well below the state averages."

According to the project's environmental document, accident data from January 2007 through December 2009 shows the collision rate for the highway stretch is below the statewide average. However, it says four of the ramps have higher accident rates. These ramps include the northbound Industrial Way offramp, northbound Sir Francis Drake Boulevard onramp, southbound Tamalpais Drive offramp and southbound Fifer Avenue offramp.

The collision data TAM has been presenting doesn't match what's in the environmental document, citing 10-year and three-year data, respectively.

Larkspur City Councilman Larry Chu said this has muddled discussions.

"Anywhere where there is a difference in perception, we need to reconcile those things," Chu said.

He said the northbound portion of the highway definitely needs to be fixed. The idea of returning to the previous alternatives and closing some of the ramps isn't quite what he has in mind.

"If you reduce the number of onramps, you end up with twice the number of cars trying to get onto the one onramp that's left," Chu said.

Ravasio said simply closing the Fifer Avenue offramp could address some of the safety concerns, as suggested by some members of the community. TAM said the flyover is necessary if the Fifer Avenue ramp remains open.

Closing the Madera Boulevard ramp is an idea Ravasio said he's less receptive to, as it's right next to the Town Center Corte Madera — a large tax generating retail outlet for the town.

He said he believes there are better options than the proposed project.

"I think there are solutions out there that are doable that don't require as much investment and as much time," Ravasio said.

 The Larkspur and Corte Madera city councils will hold a joint meeting on the Greenbrae interchange project at 7 p.m. Tuesday at the Corte Madera Recreation Center, 498 Tamalpais Drive. Submit comments to Caltrans by emailing the senior enviornmental planner at Valerie_Shearer@dot.ca.gov. Comments are due by Feb. 14.